Question

which provides evidence of universe expansion that supports the big bang theory? select the three correct answers. (2 points)
the temperature of cosmic microwave background radiation varies widely from one part of the universe to another
galaxies are moving away from each other.
the temperature of the universe is decreasing.
an enormous amount of weak cosmic background radiation has been detected in the universe
the universe is undergoing a cycle of contraction and expansion.
the temperature of the universe is increasing

Explanation:

1. Analyze "Galaxies are moving away from each other": This is Hubble's law - galaxies' redshift (moving away) shows the universe is expanding, supporting Big Bang.
2. Analyze "The temperature of the universe is decreasing": As the universe expands, it cools (like a gas expanding), so cooling supports expansion from a hot initial state (Big Bang).
3. Analyze "An enormous amount of weak cosmic background radiation has been detected in the universe": Cosmic Microwave Background (CMB) is leftover radiation from the Big Bang, uniform and weak, confirming the early hot universe and expansion.

Eliminate incorrect options:

• "The temperature of Cosmic Microwave Background radiation varies widely..." is wrong; CMB has very uniform temperature.
• "The universe is undergoing a cycle of contraction and expansion" is not Big Bang (Big Bang is a single expansion from a singularity, not cyclic in standard theory).
• "The temperature of the universe is increasing" is wrong; universe cools as it expands.

Answer:

B. Galaxies are moving away from each other,
C. The temperature of the universe is decreasing,
D. An enormous amount of weak cosmic background radiation has been detected in the universe